I'll describe exatly what's happening:

I am writting the World Editor for my MMORPG. I started it last week, and now I'm writting the layer wich you define the colision map. So, my engine so far has 2 layers.

The main layer is where I draw the isometric Grid.
The second layer is where I draw the colision points to show on the screen.

Here is the initial state of my world editor, right after I open it:



The next step is to define the colision points. We will use the 12¬? button to define the points. Then my World Editor Engine draws the Surface of my Colision Points Layer to the main surface. Using this line to draw:

Code:
Surface.BltFast( 0, 0, Surface.ClientRect, 0, FLayers[ nAux ].Surface );
code1

the result will be this:



Yesss... Since here everything is OK!! The colision points that where draw on a new surface is there! Wuhuuu!

But that is not enought.... I wan't to draw this colision surface using alpha channel. Then I'll change the BltFast method to DrawAlpha or just Draw. Then, changing that line quoted as code1 to this, and adding the colision points:

Code:
Surface.Draw( 0, 0, Surface.ClientRect, FLayers[ nAux ].Surface );
I get the following result:



Look that the colision points.. Can't see them? Yes! You can't see because the DRAW method is not doing it's job... But wait, look what happen if I resize the window, manually:



The Draw only applys when I resize my window.
That's the strange problem that is happening!

Really thaaaaaaank you!